1. Technical Field of the Invention
This invention is directed to compositions of matter containing a hydroxymethylaminoacetic acid derivative and one or more 3-isothiazolone compounds and their use to kill microorganisms and to inhibit microbial growth.
2. Description of the Prior Art
Hydroxymethylaminoacetic acid, its salts and lower alkyl esters, are known to be effective antimicrobial agents. Sodium hydroxymethylaminoacetate (CTFA Adopted Name: Sodium Hydroxymethylglycinate) is the active ingredient in the antimicrobial product marketed under the trademark Suttocide.RTM. A.
U.S. Pat. Nos. 4,105,431 and 4,252,694, disclose a group of compounds generally referred to as 3-isothiazolones, having biocidal properties. Kathon.RTM. is the trademark for a family of biocides containing these compounds as active ingredients. More specifically, the Kathon.RTM. biocides contain an aqueous mixture of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one in various weight ratios between about 2:1 and 4:1, respectively, with magnesium salts added as stabilizers. Kathon.RTM. formulations have been proposed by the manufacturer for use as a biocide in various industrial applications, such as in cooling-tower water, metalworking fluids, latex emulsions and for slime control in paper mills. They have also been proposed as a biocide for swimming pool water and as an antimicrobial preservative for toiletries, cosmetics and household cleaning products. However, a significant drawback to the 3-isothiazolone compounds is their high toxicity, particularly their high corrosiveness and skin sensitizing properties.